1. Field
The present disclosure relates to a fuel cell system, and more particularly, to a fuel cell system with a muffler to reduce noise occurring from an air feeder.
2. Description of the Related Technology
A fuel cell is a power generation device that transforms chemical energy into electrical energy, using an electrochemical reaction between hydrogen and oxygen. Examples of a fuel cell include a polymer electrolyte membrane fuel cell (PMFC) and a direct methanol fuel cell which operate at a temperature of about 100° C. and below; a phosphate fuel cell operating at a temperate of about 150° C. to about 200° C.; a molten carbonate fuel cell operating at a high temperate of about 600° C. to about 700° C.; a solid oxide fuel cell operating at a high temperate of about 1000° C. and more. These fuel cells operate on the same or similar principle, but use different kinds of fuel, a catalyst, an electrolyte, etc. from one another.
Among these fuel cells, a direct methanol fuel cell (DMFC) operates at a relatively low temperature and employs methanol directly as a fuel without using a reformer for producing hydrogen, and thus it can have a compact structure. The direct methanol fuel cell generates electricity through a chemical reaction between methanol and oxygen. During the operation of the direct methanol fuel cell, air is continuously supplied to the fuel cell to provide oxygen for the reaction.
Other fuel cells generally generate electricity by a chemical reaction between hydrogen and oxygen. During the operation of the fuel cells, air is continuously supplied to the cells because oxygen is needed to operate these fuel cells. In addition, such fuel cells may use a reformer to produce hydrogen. Likewise, air is also continuously supplied to the reformer because the reformer needs oxygen to produce hydrogen.
An air feeder is used to supply air to the fuel cells described above. In general, the air feeder includes a rotary vane pump, a diaphragm pump, or the like. Such a pump supplies air by repetitively compressing and expanding air, and thus generates a periodic or continuous noise. A muffler or silencer can be used for reducing the noise.